NEW YORK (Reuters Health) - Heavy drinkers with the alcohol dehydrogenase 1C*1 allele (ADH1C*1) have an increased risk of alcohol-related cancers, which include upper aerodigestive tract cancer and hepatocellular carcinoma, according to a report in the International Journal of Cancer for April 15th.

Alcohol dehydrogenase catalyzes a reaction that produces acetaldehyde, the chemical thought to promote alcohol-associated malignancies. Therefore, genetic variants, such as ADH1C*1, which increase the enzyme's ability to generate acetaldehyde, might be linked to an elevated cancer risk.

Dr. Helmut K. Seitz, from Salem Medical Center at the University of Heidelberg in Germany, and colleagues evaluated the ADH1C genotype in 818 heavy drinkers with various alcohol-related cancers or nonmalignant diseases. All of the patients were Caucasians who were treated at one of five German university centers between 1999 and 2003.

The ADH1C*1 allele and the ADH1C*1/1 genotype were significantly more common in subjects with cancer than in those with nonmalignant disease. Multivariate analysis confirmed ADH1C*1 allele frequency and homozygosity rate as significant predictors of alcohol-related cancer (p < 0.001).

The increased risk of alcohol-related malignancies seen with the ADH1C*1/1 genotype, ranged from 2.2-fold for head and neck cancer to 3.56-fold for hepatocellular cancer.

The new findings identify "genotype ADH1C*1/1 in Caucasians as the first known genetic marker for alcohol-related cancers in heavy drinkers," the authors conclude. "It further emphasizes the role of acetaldehyde in alcohol-associated carcinogenesis."